Motor-driven sports devices such as jet skis, snowmobiles or quads are often equipped with high-performance motors but at the same time, must also be safely manageable by less experienced operators. Furthermore, motor-driven sports devices are frequently used in crowded areas. For instance, jet skis are often employed in the vicinity of bathing beaches and before they can be used in open waters, must often travel through a strip of water near the beach that is used by careless swimmers, for instance. In order to avoid accidents, it is therefore necessary to operate the jet ski only at a restricted maximum speed in such a strip of water close to a beach. In addition, it should be ensured that a jet ski does not enter an area of the water that is heavily frequented by swimmers and which therefore does not allow the use of jet skis.
Conventionally, jet skis are equipped with a GPS receiver which is set up to ascertain the speed of the jet ski and to display it to the user of the jet ski. It is the user's own responsibility to adjust the speed to the currently traveled area, and also to ensure, on his own, that no zones are entered that are closed to jet skis.